CVE Vulnerabilities

CVE-2019-10773

Improper Link Resolution Before File Access ('Link Following')

Published: Dec 16, 2019 | Modified: Nov 07, 2023
CVSS 3.x
7.8
HIGH
Source:
NVD
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CVSS 2.x
6.8 MEDIUM
AV:N/AC:M/Au:N/C:P/I:P/A:P
RedHat/V2
RedHat/V3
7.8 IMPORTANT
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Ubuntu
MEDIUM

In Yarn before 1.21.1, the package install functionality can be abused to generate arbitrary symlinks on the host filesystem by using specially crafted bin keys. Existing files could be overwritten depending on the current user permission set.

Weakness

The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.

Affected Software

Name Vendor Start Version End Version
Yarn Yarnpkg * 1.21.1 (excluding)
Red Hat Quay 3 RedHat quay3/clair-jwt:v3.2.1-1 *
Node-yarnpkg Ubuntu disco *
Node-yarnpkg Ubuntu eoan *
Node-yarnpkg Ubuntu groovy *
Node-yarnpkg Ubuntu hirsute *
Node-yarnpkg Ubuntu impish *
Node-yarnpkg Ubuntu kinetic *
Node-yarnpkg Ubuntu trusty *
Node-yarnpkg Ubuntu upstream *

Potential Mitigations

  • Follow the principle of least privilege when assigning access rights to entities in a software system.
  • Denying access to a file can prevent an attacker from replacing that file with a link to a sensitive file. Ensure good compartmentalization in the system to provide protected areas that can be trusted.

References